Fabrication and Application of 1.7KV SiC-Schottky Diodes

Abstract

High voltage 4H-SiC Ti Schottky junction barrier schottky (JBS) diode with breakdown voltage of 1700 V and forward current of 5 A has been fabricated. A low reverse leakage current below 3.8×10-5A/cm2at the bias voltage of -1700 V has been obtained. The forward on-state current was 5 A at VF= 1.7 V and 15.8 A at VF= 3 V. The active area is 1.5 mm × 1.5 mm. The turn-on voltage is about 0.9 V. The on-state resistance is 3.08 mΩ·cm2. The doping and thickness of the N-type drift layer and the device structure have been performed by numerical simulations. The SiC JBS devices have been fabricated and the processes were in detail. The die was assembled in a TO-220 package. The thickness of the N- epilayer is 17 µm, and the doping concentration is 3.2 × 1015cm−3. The number of floating guard p-rings was chosen to be 25, the distance between the rings was chosen to be 0.7 µm ~ 1.3 µm and the width of the p-rings is 2.5 µm. We use the PECVD SixNy/SiO2as the passivation dielectric and a non photosensitive polyamide as the passivation in the end. The reverse recovery current Irwas 1.26A and the reverse recovery time Trrwas 26ns when the diode was switched from 5A forward current to a reverse voltage of 700V. The reverse recovery electric charge Qrrof 16nC was obtained.

Defects in Ge Doped SiC Crystals

“…Key words: physical vapor transport; Ge doping; SiC crystal; lattice parameters 碳化硅(SiC)作为第三代半导体材料的代表, 相 对于常见的 Si 和 GaAs 等半导体材料, 具有宽带隙、 高热导率和高饱和电子漂移速率等优点, 已成为耐 高温、耐高压、大功率和抗辐照的半导体器件的优 选材料 [1][2][3] , 是目前半导体材料领域富有应用前景 的材料之一, 可应用于半导体照明、航空航天探测、 电力电子、微波通讯、核能探测及开发、卫星和汽 车发动机等高温及抗辐射领域 [4] 。 目前 SiC 的掺杂研究主要集中在 n 型杂质(氮、 磷等) [5][6][7][8][9] 和 p 型杂质(硼、铝等) [10][11][12] 的工作上, 而较 少研究 IV 族杂质元素(锗、锡等)的掺杂对于 SiC 晶 体材料的影响。2001 年, Katulka 等 [13] 采用掺 Ge 碳 化硅衬底制作的二极管(SBD)和双极型晶体管(BJT), 具有优良的性能。由于 Ge 元素的存在可以降低电 子器件接触电阻, 提高电子迁移率和寿命, 因此掺 Ge 碳化硅基底的异质结晶体管(HBT)中的电流增益 提高了 50%, 并且初期电压增加了 33% [14] 。 2015 年, Ghosh 等 [15]…”